22 PRACTICAL TREE REPAIR 



trunk, standing out like a flexed muscle, connect- 

 ing a large limb with a principal root, it is obvi- 

 ously undesirable to cut across it. Removing the 

 cambium would rob the root of its due supply 

 of digested sap, and removing the sapwood would 

 cut off the water supply of the limb above it. In 

 the same way, a wide incision should not be made 

 just above a thrifty root, nor just below a large 

 limb. In case a series of holes must be cut into 

 a tree in order to remove decay, it is probably 

 best to cut one directly above another, or, if the 

 tree is twisted, in a spiral. By that arrangement 

 there is a minimum of interference with the flow 

 of sap. There is considerable likelihood, how- 

 ever, that the bark between the incisions will die, 

 in which case it should be cleaned away, and the 

 exposed wood should be painted. 



